A pig iron and ore process that depends upon the rapid oxidation of the impurities contained in pig iron by a liquid, highly ferruginous slag and that is carried out in the basic open-hearth furnace, generally of the tilting type. The essential feature of the process is to retain a certain amount of metal in the furnace (1) to dilute the impurities contained in the additions of pig iron, and (2) to supply the heat necessary to keep the slag very fluid.